dental cements

dental cements traditionally used

1. Guidie iBy:-yDryLuyaBl -tygMleBi
Guided By :- Dr Lalitagauri M andke Presented By :- Dr Aditya Shinde
Guided By :- Dr Lalitagauri Mandke
(1-71)

2. CONTENTS
Introduction
Definition
History
Ideal properties
Classification
Based on Ingredients & Application (Craig)
Based on Bonding Mechanism (William O'Brien)
Based on Setting Reaction (Anusavice)
Silicate cement
Zinc phosphate cement
Modification
Fluoridated cement
Copper cement
Silicophosphate cement
Zinc polycarboxylate cement

3. Zinc Oxide Eugenol cement
Modification
Reinforced Zinc Oxide Eugenol
EBA
Calcium Hydroxide cement
Conclusions
References

4. INTRODUCTION
In last 20 years there has been an explosion of different
types of dental cements that have become available to
practicing dentist ,many of them tailored for specialized
types of restoration. In fact ,there are so many products to
choose from the task ,can become confusing.
Dental cements, in the recent years has become
restricted to those materials which are employed to bond
inlays, crowns, bridges, posts and facings in or on the tooth
and to retain orthodontic bands and retainers, however
secondary applications of these cements include cavity
linings, bases and temporary fillings, endodontic sealer.

5. These different applications make varying
demands on manipulative properties, working
and setting times, and resistance to mechanical
breakdown and dissolution. Thus some materials
are better suited to some application than
others.
Many of these materials are supplied in
powder/liquid form and set by an acid-base
reaction, but this is not universally true.
As yet, there is no ideal dental cement. Each
material must be used on its merits with
knowledge of its limitations.

6. DEFINITIONS

7. oA substance that hardens to act as
a Base, Liner, Filling material or
Adhesive to Bind Devices and
Prosthesis To Tooth Structure To
Each Other .

(Anusavice)

8. Dental Cement TimelineDental Cement Timeline
1850 1900 2000
ZOE
ZPSC
PCC
GI
RC
RMGI
Compomer
1950
CH

9. History…
1873- Silicate cement by Fletcher
1873- Zinc oxide and clove oil by Chisolm
1879- Zinc phosphate cement by Dr Pierce
1930- Calcium hydroxide paste by Hermann
1968-Polycarboxilic cement by Dennis Smith
1971-Glass ionomer cement by Wilson and
Kent

10. Ideal properties of dental cements
Should be strong and hard.
Able to protect pulp
Should be insoluble in saliva & liquids taken in mouth.

Should be dimensionally stable.
Should be adhesive .
Should be non porous .
Should be biocompatible and non irritant.
Co-efficient of thermal expansion should be equal to the
tooth structure.
Should not be affected by thermal changes and
moisture.
Should be easy to manipulate.

11. Water based cements
oGlass & Resin modified glass ionomer
oZinc Polyacrylate
oZinc Phosphate
Resin based cements
oComposite & adhesive resin
oCompomers
Oil based cements
oZinc Oxide Eugenol
oNon Eugenol -Zinc Oxide

12. Water based cements
1) Glass & Resin modified glass ionomer cement :
Class V restoration
- Retention of- Conventional alloy based restoration
Orthodontic bands
Alumina or zirconia based all ceramic restoration

- High strength bases
- Long term provisional restoration
2) Zinc Polyacrylate:
- Retention of -Conventional alloy restoration
-Orthodontic bands
-Pediatric stainless steel crown
- High strength bases
- Long term provisional restoration
3) Zinc phosphate :
- Retention of- Conventional alloy based restoration
-Orthodontic bands
- High strength bases
- Long term provisional restoration

13. Resin based cements
1. Composite & adhesive resin :
- Bonding- Conventional alloy based restoration
-Ceramic crowns, bridges ,veneers, inlays,
onlays.
- Post & cores
- Retention of - Provisional restoration
- Orthodontic bands
2. Compomers:
- Bonded conventional alloy based restoration
- Retention of - Alumina or zirconia based all ceramic
restoration
- Orthodontic bands
- High strength bases

14. Oil Based Cements
Zinc Oxide Eugenol :
High strength bases
Provisional restoration
Root canal sealers
Gingival tissue packs
Surgical dressing
Non Eugenol -Zinc Oxide:
Provisional restoration
Root canal sealers
Gingival tissue packs
Surgical dressing

15. Based on the bonding mechanism
(Williams O'Brien. 2002 & Richard van Noort)
Phosphate based :
Zinc phosphate cement
Modified zinc phosphate cement
Fluoridated cement
Copper cement
Silicophosphate cement
Phenolate based :
Zinc oxide eugenol cement
Reinforced zinc oxide eugenol
EBA and other chelate cements
Calcium hydroxide chelate cement
Polycarboxylate based:
Zinc polycarboxylate cement
Glass ionomer cement
Methacrylate based:
Acrylic cements
BIS-GMA type cements

16. Classification based on setting reaction
( Skinners)
Acid Base Reaction –
Zinc phosphate
Zinc polycarboxylate
Zinc oxide eugenol
Glass ionomer cement
Light / Chemical activities
Polymerization and acid base reaction

Resin modified glass ionomer cement
 Compomer
Resin cement.

17. Classification (E.C. Combe 6
th
edition)
Acid base reaction cements.
Zinc phosphate
Zinc polycarboxylate
Zinc oxide eugenol
Silicate
Glass ionomer cement
Polymerising materials
Acrylic polymer
Cyanoacrylates
Dimethacrylate polymers
Polymer ceramic composites
Other materials
i) Calcium hydroxide
ii) Guttapercha
iii) Varnishes.

18. Silicates
Introduced in 1903 as
anterior filling materials.
Silicates are attacked
by oral fluids and in
time degrade,
They may not be
considered permanent
restoration.
The uses of silicate
cements diminished
with the advent of
composite resins and
development of GIC.

19. Powder:
 Silica
Alumina
Fluoride compounds
Calcium salts
Fluoride Flux -
To permit proper sintering
of the other ingredients.
Liquid :
Phosphoric acid
Water
Buffer salts

20. Setting Reaction
Powder mixed with liquid
Powder attacked by acid liquid releasing Ca, Al, Fl
ions
Metal ions precipitate as phosphate
cement matrix inclusive of Fl salts

21. Advantages
It exhibit good esthetic qualities .
Anticariogenic property.
Analogues to topical applied fluoride solution.
DisadvantagesDisadvantages
It lacks stability in oral fluids with loss of esthetic qualitiesIt lacks stability in oral fluids with loss of esthetic qualities
Rubber dam is essential for successful silicate Rubber dam is essential for successful silicate
restoration.restoration.

Irritant to pulp.Irritant to pulp.

22. Zinc Phosphate cement
Introduced over a
century ago It is the
oldest luting cement.
Longest clinical track
record to compare
with newer systems.
Synonyms `Crown and
Bridge’ and “Zinc
oxyphosphate’

23. ZINC PHOSPHATE CEMENT
COMPOSITION
POWDER
Zinc Oxide - Principle Ingredient
Magnesium Oxide - reduces the temp. of calcification process
2.10% aids in sintering.
Oxides of
Bismuth, Calcium or - Impact a smoothness to freshly mixed
Barium Cement mass.
In large quantities lengthen the S.T
Silicon Dioxide - In active filler
 LIQUID
Phosphoric acid - 45-64% Reacts with ZnO
Water - 30 – 55% Increases Rate of reaction
Aluminum - 2.3% Essential to the cement forming reaction –
Zinc - 0.9% Moderates reaction between powder and
Liquid allows adequate working time

24. CLASSIFICATION
(Anusavice 9
th
edition )
Type I
-Fine grained for luting
-Film thickness should
be less than 25 um

Type II -
- Medium grained for
luting and filling
- Film thickness
should be more than
40um

25. Manipulation
Dispense the cement P/L :1.4
gm / 0.5 ml.
 Divide the powder in one
corner of the glass slab into
increments depending on
product.
Dispense the correct amount of
liquid, to area of the slab away
from the powder.
Add the powder to liquid in
portions at 15 sec intervals for a
mixing time 60-120 sec

26. Mix it over a large area of
the slab with a flexible
metal spatula.
Test the consistency of the
cement before adding
the last portion of powder.
Only part of that portion
of powder may be
necessary to reach the
desired consistency.
The cementing strings
about one inch above the
slab.

27. NOTE : Powder liquid reactions ,an accelerated by the
presence of heat (exothermic reaction)
Liquid consists of partially centralized dilute Phosphoric
acid. .
When this liquid is exposed to a humid atmosphere, it will
absorb water. Whereas exposure to dry air tends to result
in a loss of water which will alter the property of cement.

28. Frozen Slab Technique
Practical way to increase the working time and reduce
the setting time of zinc phosphate cement.
50% increased powder/liquid ratio.
Mixing in a frozen glass slab at 21
0
C.
Effective when multiple castings are to be cemented.
Excess of cement is easy to clean up .
But decrease in compressive strength.

29. SETTING REACTION

Exothermic reaction
Powder & liquid mixed
Phosphoric acid attacks the surface
Release of zinc ions & reaction of Al with phosphoric acid
Al & Zn ions react with phosphoric acid
Zinc alumino phosphate gel
and surrounds with un reacted particle
Thus the set cement is a cored structure consisting primarily of un-
reacted Zinc Oxide particles embedded in a cohesive amorphous matrix
of zinc aluminophosphate.
Water is critical to reaction.

30. Properties
Compressive strength -104 Mpa
Tensile strength -55 Mpa
Modulus of elasticity – 13.7Gpa ( stiff & resistance to
deformity )
Retention is mechanical
At insertion PH at 2 min – 2
at 24 hrs – 5.5
Damage to pulp occurs during first few hrs of insertion.
WT
MT
ST
5 min5 min
2.5 -8 min2.5 -8 min
1.5 -2 min1.5 -2 min

31. Advantages
Most popular for cast restorations
Adequate strength
Reasonable working time
Excess material can be easily removed
Acceptable effect over the dental pulp
Manipulation less critical than other cements.
Disadvantages
Pulp irritation
Lack of antibacterial action
Brittleness
Lack of adhesion
Solubility in acid fluids

32. Variations in Zinc Phosphate Cement
Fluoridated cement:
oSmall % of stannous fluoride.
oLower strength & higher solubility than zinc phosphate.
oFluoride release continues over long period & uptake.
reduces enamel solubility ,increases harness.
oThis activity should reduce the incidence of enamel
decalcification under orthodontic bands.
oUsed in orthodontic band cementation.
Copper/Silver cement:
oConsists of proportion of red or black cuprous oxide or
copper salts or silver salts to zinc oxide powder.
oLiquid same as conventional.
oUsed in past due to germicidal action.
o Were discontinued due to staining of teeth.

33. Silicophosphate cement :
Combination of zinc phosphate & silicate cement.
Contains small amounts of mercury compounds.
Composition:
Silicate glass & minor amount of zinc oxide,13-25% fluoride
Liquid contains 50% phosphoric acid,45% water,4-9% zinc, 2% Al.
Advantages :
Better & toughness than zinc phosphate.
Fluoride release & degree of translucency.
Lower solubility & better bonding.
Disadvantages :
Less satisfactory mixing & rheological properties
Leading to higher film thickness & greater potential for pulp
irritation.
Used for cementation orthodontic bands & restoring non vital teeth

34. Zinc Polycarboxylate Cement
It is the 1
st
adhesive material
developed in dentistry.
Advantages over the
traditional ZnPO
4
•

Compatibility with pulpal
tissue
• Adhesion to tooth
structure.

35. ZINC POLYCARBOXYLATE CEMENT
POWDER: (Same as zinc phosphate)
-Zinc oxide – Main ingredient
- Stannous oxide –Replaces magnesium oxide
- Silica, Alumina or Bismuth - Filler
- Stannous fluoride – 4.5% improves the
manipulation,
characteristics, strength.
-Sodium fluoride - 1% Anticariogenic property
LIQUID
- Aqueous solution of Polyacrylic acid
- Co-polymer of acrylic acid
- Other carboxylic acid ( itconic acid) – stabilizes the liquid

36. ZINC POLYCARBOXYLATE
MANIPULATION:-
Mixed at a P/L of 1.5 :1
The consistency is creamy compared with that of zinc phosphate
cements.
The correct consistency is found in a mix that is viscous but that
will flow back under its own weight when drawn up with spatula.
 Dispensing of the liquid should be done immediately before
mixing to prevent evaporation of water and subsequent
thickening.
The mixed cement should be used only till appears glossy on the
surface. Once the surface becomes dull, the cement develops
stringiness and the film thickness becomes too great to seat a
casting completely.

37. Non absorptive surface, such as glass slab or treated
paper, will keep all the liquid available for the
reaction and facilitate spatulation.

Polyacrylate cements should be mixed within 30-60
sec, with half to all of the powder incorporated at
once to provide the max thickness.
The strength of the mixed cement is not compromised
by this technique.

38. Setting Reaction
Surface dissolution of particles by acid
Release of Zn, Mg ,Sn ions
Bind to polymer chain by OH group
Reacts with carboxylic group
Cross linking of polymer chain
Amorphous gel particle with unreacted particle dispersed

39. Properties
Compressive strength – 55 -67 Mpa
Tensile strength –slightly higher than ZnPO
4
Modulus of elasticity -2.4 – 4.4 Gpa (less
stiffer
& less brittle than ZnPo
4
)
Low soluble in oral fluids than ZnPO
4
Excellent biocompatibility with pulp
2.5 min2.5 minWTST
MT
30-60 sec
6 -9 min6 -9 min

40. Advantages :
Low level of irritation
Good adhesion to tooth substances & alloys.
Good strength ,solubility & film thickness
compare to zinc phosphate.
Disadvantage
Need for accurate proportion, more critical
manipulation
Lower compressive strength & greater visco-
elasticity than zinc phosphate.
Short working time & need clean surface to use
adhesion potential (technique sensitive).

41. Zinc Oxide Eugenol
Extensively used in dentistry
since 1890’s .
Least irritant of all the dental
materials.
Poor strength when compared
to zinc phosphate.
It has sedative effect on
exposed dentin.

42. ZINC OXIDE EUGENOL
ZnOZnO Principal Principal
Ingredient Ingredient
White rosin White rosin Brittleness Brittleness
of set of set
cementcement
Zn acetate Zn acetate Accelerator Accelerator
strength – strength –
up to 1%up to 1%
MgOMgO ModifierModifier
Zn stearate Zn stearate Plasticizer Plasticizer
Eugenol Eugenol Reacts with ZnO Reacts with ZnO
Olive Oil Olive Oil Plasticizer (85% Plasticizer (85%
Eugenol) Eugenol)
Water Water Initiator Initiator
Acetic Acetic
acid/alcacid/alc
ohol ohol
To accelerate To accelerate
setting – about 1% setting – about 1%
POWDER LIQUID

43. CLASSIFICATION (ADA Sp. No 30)
Type I Type I Used for Temporary cementation Used for Temporary cementation
Type II Type II Used for Long Term cementation of Used for Long Term cementation of
fixed prosthesisfixed prosthesis
Type III Type III Temporary Filling/ Thermal Temporary Filling/ Thermal
insulating base insulating base
Type IVType IVIntermediate Restorations and Intermediate Restorations and
Cavity linersCavity liners

44. ZINC OXIDE EUGENOL CEMENT
MANIPULATION
Temporary cements (Type I) & Liners ( Type IV )
A typically two paste systems.
Dispense equal lengths of the accelerators and base
pastes on a paper pad / glass slab
Continue mixing until a uniform colour is achieved.
Long term Zinc oxide Eugenol Cements (Type – II)
A powder & liquid system.
Shake the powder bottle gently, then dispense the
powder with the supplied scoop and the liquid with a
dropper.
Mix on a glass slab or treated paper pad with a metal
spatula. Incorporate the powder into the liquid all at
once and mix for 30 sec.
 Coat the patient’s lips and adjacent teeth with petroleum
gel before application of the cement. Oil of orange is a
solvent useful in removing set cement.

45. ZINC OXIDE EUGENOL
SETTING REACTION
zinc dioxide hydrolysis

zinc hydroxide
eugenol

zinc eugenol
Water is needed to initiate the reaction and it is also a by-
product of the reaction. So the reaction proceeds more
rapidly in a humid environment.
The setting reaction is also accelerated by the presence of
zinc chelate dehydrate.
Acetic acid is a more active catalyst for the setting reaction
than is water because it increases the formation rate of zinc
hydroxide. High atmospheric temperature also accelerates.

46. Advantages:
Minimal pulp reaction.
Good sealing properties
Strength adequate for lining material & luting single
restoration & retainers, with good retention form.
Disadvantages:
Hydrolytic breakdown under exposure to oral fluids
Inflammatory reaction in soft tissue
potential allergic response
Minimal mechanical properties for luting
May soften & discolor

47. ZINC OXIDE EUGENOL
Modifications of ZOE :
 Resin Reinforced Zinc
Oxide Eugenol Cement

EBA and other Chelate
Cements

48. RESIN REINFORCED ZINC OXIDE
EUGENOL CEMENT
COMPOSITION :

POWDER :
Zinc powder – 80.0%
Poly methyl-methacrylate – 20.0%(bond to other components)
Zinc stearate - traces (accelerator)
Zinc acetate
Thymol & hydroxyquinoline – traces (antimicrobial agent)
LIQUID:
Eugenol – 85%
Olive oil – 15% -(as plasticizer ,masks irritating effect of eugenol).

49. PROPERTIES
Film thickness - 25-75 um
Compressive strength- 35-55 MPa
Tensile Strength - 4 MPa
Modulus of elasticity - 2-3000 MPa
Water immersion reduces the mechanical
properties due to loss of eugenol.
Mechanical retention of crowns of ZOE
cement is less than Zinc phosphate cements.
 An 83.5% success rate was noted for
polymer reinforced cement after 7 years.
WTST
MT
5 min
7-9 min
2 min

50. EBA AND OTHER CHELATE CEMENTS
COMPOSITION
Powder
ZnO
Aluminium oxide/other
mineral fillers – 20-30%
Polymeric reinforcing agent
(poly methyl
methacrylate)
Barium sulphate -
radiopacity
Liquid
O- ethoxy benzoic acid 50-
60%
Eugenol – Remaining part

51. PROPERTIES
Working time and setting time – 7-13 min.
Film thickness – 40-70 um
Tensile strength – 6-7 MPa
Modulus of elasticity – 5000 MPa
Shows visco -elastic properties with very low strength and
large plastic deformation at slow rates of deformation at
mouth temperatures (37 C)
This is why EBA cement retention values for orthodontic
bands, although superior to those of other zinc oxide
eugenol type materials, are considerably less than those
of zinc phosphate cement.
Exposing EBA cements to moisture results in greater oral
dissolution than with other cements.

52. ADVANTAGES
•Easy manipulation
•Long working time
•Good flow characteristics & strength
characteristics
•minimal irritation to the pulp
•Best suited to luting of restorations with good fit
retention where there is no under stress and for
cavity bases.
DISADVANTAGES
•More critical proportioning
•Hydrolytic breakdown in oral fluids
•Liability to plastic deformation
•Less retention than zinc phosphate cements

53. Applications
 Luting agent
 Cavity bases

54. Non- Eugenol cement
(Cavit)
A premixed non eugenol paste used for
temporary restorations & cavity bases.
Contains – Zinc oxide
Zinc sulphate
Calcium sulphate
Glycol acetate
Poly vinyl acetate
Triethanolamine
Red pigments

55. Setting reaction initiated by saliva & water.
 Better sealing into cavity walls due to hydroscopic properties.
 Minimum thickness of atleast 3 to 3.5 mm required.
It is not satisfactory material for cementation.
When inserted into dry cavity it creates negative pressure,
causing aspiration of odontoblast leading to pain.
PH same as ZOE.

56. Calcium Hydroxide
INTRODUCTION

It has multipurpose use
though not used as
permanent restorative
material
Ca(OH)2 is a white
odorless powder
Mixed with water or saline
to a form a paste.
It is strongly alkaline with
a PH of 12.5
It is classified as an
astringent in
Pharmacology.

57. HISTORY
In 1936 Hermann introduced Ca(OH)2
to promote healing in many clinical
situations
 The introduction of this material in the
US was by Teuscher and Zander in
1938.
Successful pulpal healing using
Ca(OH)2 is between 1934 & 1941.

58. CHARACTERISTICS OF
Ca(OH)2
Molecular weight of 74.08.
Radiolucent
Specific Gravity of 2.34
PH 12.5 at 25 C
Very slightly soluble in water,
soluble in glycerin syrup and acids.

59. MECHANISM OF ACTION
High alkaline PH(11-13) Causes neutralization
of acids produced by microorganisms.
Antibacterial effect due to high PH.
Seals the dentinal tubules offering dentin
protection.
Induces reparative dentin below existing
dentin.
Biocompatibility & calcific barrier enabling to
maintain pulp vitality.
Ca(OH)2 maintains a local state of alkaline by
that is necessary for bone/dentin formation .

60. On Vital dentin
Considerably reduces the permeability of exposed dentin
for penetration of bacterial components towards the pulp.
 This may be due to
 Coagulation of proteins in dentinal
tubules
 Due to secondary dentin formation
 It has an antibacterial effect

61. On Carious Dentin
Ca(OH)2 has a strong antibacterial effect on the
contaminated soft carious dentin.
ON EXPOSED PULP
Low grade irritation due to coagulative necrosis
caused by Ca(OH)2 leading to hard tissue
differentiation in the pulp to calcific barrier
formation.

62. DIFFERENT FORMS OF Ca(OH)2 AVAILABLE
1) DRY POWDER
Dry powder of Ca(OH)2 medicinal grade. Free from
impurities and contaminants is available. The powder could be
supplied as such or mixed to a paste with either distilled water
or normal saline. Mixing with water or ortho ethoxy benzoic
acid is avoided as the reaction is too fast for convenient
clinical use.
2) LIQUIDS
They are supplied in bottles. Resinous solution of Ca(OH)2
are used as liners. The combination or resin film with alkaline
Ca(OH)2 provides a protective film having better physical
integrity as well as chemical neutralizing capacity for acids.

63. 3) NON – SETTING PASTES
They are supplied in Jar’s or inject able single paste
system. In these materials, calcium hydroxide is not
reacting with other ingredients of the paste. The other
ingredients are only carriers and the availability of
free Ca and OH ions from the preparation will be
more.

64. 4) SETTING PASTE
1.Chemically Activated Ca(OH)2 paste system
Base
1) Calcium hydroxide – 51%
2) Zinc oxide -9.23%
3) Zinc Stearate – 0.29%
4) Ethylene Toluene Sulphonamide -39.48%
CATALYST
Titanium oxide – 45.1%
Calcium Tungstate -15.2%
Barium sulphate – 4%
Glycol salicylate – 35.7%

65. 2. Visible light activated Ca(OH)2 – Single paste
system.
CaOH
BaSO
4
UDMA Resin
Camphorquinous
5) SLOW SETTING Ca(OH)2 Pastes.
Root Canal Sealer materials
Ca(OH)2 can be used as a sealer to coat the Would of the pulp
space and form a hermetic seal
Ex – Calcibiotic
Root Canal Sealer paste (CRCS Paste)
Containing – ZOE, Ca(OH)2

66. VEHICLES
When CaOH2 powder is mixed with a suitable vehicle a paste is
formed.
The vehicles play a major role in the over all process because it
determines the velocity of ionic dissociation causing the paste to
re-establish and restore at various rates by the peri apical tissues
within the root canal.
Types of Vehicles are used
 Aqueous Vehicles – Water
Saline
LA solution
 Viscous Vehicles - Glycerine
Polyethyl glycol
 Oily vehicles - Olive Oil
Fatty acids.
Eugenol.

67. Direct PulpDirect Pulp CappingCapping
Indirect Pulp CappingIndirect Pulp Capping
BaseBase
PulpotomyPulpotomy
LinerLiner
Root canal sealerRoot canal sealer
Prevention & treatment of ResorptionPrevention & treatment of Resorption
Repair in perforationRepair in perforation
Intra Canal Medicament Intra Canal Medicament
Horizontal #Horizontal #
Root fractureRoot fracture
ApexificationApexification
CALCIUM HYDROXIDECALCIUM HYDROXIDECalcium Hydroxide

68. Adverse Effects
Calcifications in pulp.
Internal resorption.
Ankylosis.
Increased brittleness of dentin.

69. Summary
Zinc phosphate cement has long served as the universal luting
cement. Its advantages includes good handling
characteristics and a proven longevity in the oral cavity when
it is used for cementation of well designed and well fitting
restorations.
Its disadvantages include pulp irritation, lack of adhesiveness
to tooth structure, and lack of anticariogenic properties.
ZnPO
4
is not suitable when the mechanical retention poor or
when the aesthetic demand is high.
The main advantage of improved Zinc Oxide Eugenol cement
is their biocompatibility. The physical and mechanical
properties and the handling characteristics generally inferior
to those of other long term luting cements.

70. The properties of zinc Polycaroxylate cement are good compared
with those of ZnPO4. The outstanding characteristics are their
blandness to the pulp and formation of an adhesive bond to tooth
structure.
Disadvantages include the short WT, SF and limited capabiling for
fluoride release. Their short W.T limits their used to single units or
three unit fixed partial dentures (bridges). These cements have
decreased in popularity, but they are still often used for patients
who have reported a history of postoperative sensitivity.
Calcium hydroxide is not a restorative material by itself many a
time , but forms a part of restoration. Its fascinating osteogenic &
dentinogenic potential have elevated its status as unique material
used in dentistry.

71. REFERENCES
Theodore M. Roberson: Sturdevant’s Art and Science of Operative
Dentistry 4
th
& 5
th
edition.
Skinners
Kennith J Anusavice: Phillips’ Science of Dental Materials 11
th

edition & 9
th
edition.
S Mahalaxmi : Materials used in dentistry,2013.
Robert G. Craig and John. M: Restorative Dental Materials 11
th

edition & 12
th
edition.
Joyre Reese , Thomas Valege :Restorative Dental Materials :An
Overview, 2
nd
edition
Williams O'Brien. 2002 & Richard van Noort
E C Combe 6
th
edition.